Color cathode ray tube and method of manufacturing the same

Abstract

A color cathode ray tube is disclosed in which a coating containing an aluminum-phosphorus compound and fine particles of at least one of tungsten oxide and bismuth oxide is formed on the surface of a shadow mask on the side of an electron gun.

What is claimed is: 
     
       1. A method of manufacturing a color cathode ray tube, said method comprising the steps of: preparing a suspension containing an aluminum-phosphorus compound and fine particles of at least one of tungsten oxide and bismuth oxide,   forming a coating film of said suspension on a surface of a shadow mask, said surface to be arranged facing an electron gun from which electron beams are incident, and   calcining said coating film to form a coating on said shadow mask.   
     
     
       2. A method according to claims 1, wherein said fine particles of at least one of tungsten oxide and bismuth oxide account for 15 to 60 wt % of a total coating weight. 
     
     
       3. A method according to claim 1, wherein a diameter of said fine particles of at least one of tungsten oxide and bismuth oxide is 0.2 to 2 μm. 
     
     
       4. A method according to claim 1, wherein said suspension further contains boron oxide. 
     
     
       5. A method according to claim 4, wherein the boron oxide accounts for 10 to 25 wt % of an amount of aluminum oxide contained in the aluminum-phosphorus compound. 
     
     
       6. A method according to claim 1, wherein said suspension also includes at least one of aluminum oxide and magnesium oxide in an amount corresponding to 70 to 140 wt % of a stoichiometric excess amount of phosphoric acid with respect to aluminum oxide contained in the aluminum-phosphorus compound. 
     
     
       7. A method according to claim 1, wherein said coating has a film thickness of 2 to 20 μm. 
     
     
       8. A method according to claim 8, wherein a calcination temperature in the calcining step is 180 to 600° C. 
     
     
       9. A method according to claim 1, wherein a calcination time in the calcining step is 30 to 120 minutes.